Machine for mass production of both medium and short lengths of tubing

ABSTRACT

A versatile high-speed drum-type tube cutting machine having a series of axially spaced endless bands for rotating the tubes and holding them in parallel relation between the radial vanes of the drum and rotary knife means adjacent the drum for cutting the rotating tubes. The machine can be used to perform multiple cuts during each revolution of the drum and can also be used to effect rapid cutting of very short lengths. In the latter case the endless band means is skewed to effect axial feeding of the tubes against an adjustable stop near the end of the drum and a rotary knife is arranged to cut one short piece off the end of each tube during each revolution of the drum.

United States Patent 1 Molnar Mar. 19, 1974 MACHINE FOR MASS PRODUCTIONOF BOTH MEDIUM AND SHORT LENGTHS OF TUBING [76] Inventor: MichaelMolnar, 4381 Valley Forge Dr., Fairview Park, Ohio 44126 22 Filed: Apr.7, 1972 [21] Appl. No.: 241,956

[52] US. Cl 82/46, 82/85, 82/89, 82/101, 82/102, 83/411 R, 83/713 [51]Int. Cl. B26d 7/06, B23b 5/14 [58] Field of Search 82/46, 79, 83, 85,89, 82/101, 102; 83/411 R, 713

[56] 1 References Cited UNITED STATES PATENTS 3,302,500 2/1967Hackenberger 82/97 2,553,136 5/1951 Eisler 82/102 2,701,015 2/1955Gottschalk 82/102 12/1962 Dearsley 83/402 923,552 6/1909 Mill 82/853,084,578 4/1963 Hartford 82/101 X Primary Examiner-Wi1lie G.Abercrombie [57] ABSTRACT A versatile high-speed drum-type tube cuttingmachine having a series of axially spaced endless bands for rotating thetubes and holding them in parallel relation between the radial vanes ofthe drum and rotary knife means adjacent the drum for cuttingtherotating tubes. The machine can be used to perform multiple cutsduring each revolution of the drum and can also. be used to effect rapidcutting of very short lengths. In

the latter case the endless band means is skewed to effect axial feedingof the tubes against an adjustable stop near the end of the drum and arotaryknife is arranged to cut one short piece off the end of each tubeduring each revolution of the drum.

8 Claims, 11 Drawing Figures PAIENTED MAR l 9 W4 SHEU 2 BF 6 PAIENTEUMAR I 9 I974 SHEET l 0F 6 Hoe FIG. 6

sum 5 or 6 FIG. 7

PATENTEDHAR 19 I974 i l I 78 L MACHINE FOR MASS PRQDUCTION OF BOTHMEDIUM AND SHORT LENGTHS OF TUBING The present invention relates to animproved tube cutting apparatus and more particularly to a high-speeddrum-type tube cutter designed for mass-production cutting of ordinarytube lengths, which cutter may be adjusted to cut very short tubes oneat a time from longer lengths of tubing at high speed.

It is conventional to out long tubes with a rotating knife whilesupporting the tubes on rotating mandrelsrotate the tubes and to holdthem in parallel relation against the periphery of a rotating drum.However, such automatic machines do not function satisfactorily whencutting very short lengths (for example,'lengths less than the outsidediameter of tube);

The improved automatic tube cutting machine of the present invention isconstructed to function efficiently when cutting tubes with a widevariety of lengths and diameters including those of short length andthose of very small diameter The machine includes one or more rotatingknives, a rotating drum with endless bands to engage the tubesandtorotate them as they engage the knife, and means for advancing the tubesaxially against a stop. The latter function may be effected by a skewedendless band, and extremely short pieces may becut one at a time from alength of tubing by placing the rotating knife near the stop. Themachine is preferably constructed so that it may be adjusted forhigh-speed cutting of ordinary tube lengths using a multiplicity ofcutters and may also be adjusted for cutting of the shorter lengthsusing one cutter. The same machine may also be modified to permitcutting of tubes of extremely small diameter. I I I An object of thepresent invention is to provide a simple versatile tube cutting machinefor h igh speed cutting of tubesof widely varying sizes.

A further object is to provide an automatic tubecutting machine whichoperates effectively when cutting short lengths. Y r I I r I Anotherobject of the invention is toprovide a highspeed automatic tube cutterwhich will accommodate a substantial number of rotating knives'forconventional cutting and which may readily be adjusted to cut tubes ofextremely short length.

Another object is to provide a reliable method of and apparatus forcutting tubes of extremely small diameter.

These and other objects, uses and advantages of the invention willbecome apparent to those skilled in the art from the following drawings,description and claims.

In the drawings:

FIG. 1 is a top view of a tube cutting machine constructed according tothis invention on a reduced scale;

FIG. 2 is a side elevational view of the machine of FIG. 1;

FIG. 3 is an end elevational view of the machine with parts omitted, anoptional hopper being shown in broken lines;

FIG. 4 is a fragmentary vertical sectional view of the machine on alarger scale;

FIG. 5 is a fragmentary vertical sectional view on the same scale asFIG. 4; I

FIG. 6 is a fragmentary horizontal sectional view taken substantially onthe line 6-6 of FIG. 4;

FIG. 7 is a fragmentary vertical sectional view taken substantially onthe line 7-7 of FIG. 4.

FIG. 8 is a fragmentary vertical sectional view showing a modified formof the invention;

FIG. 9 is a fragmentary horizontal sectional view taken substantially onthe line'9-9 of FIG. 8;

FIG. 10 is a fragmentary vertical sectional view taken substantially onthe line 10-10 of FIG. 9 and on a larger scale; and

FIG. 1 1 is a fragmentary cross sectional view showing a portion of therotary knife.

Referring more particularly to the drawings in which like parts areidentified by the same numerals throughout the several views, FIGS. 1-3show external views of a tube cutting machine A constructed according tothe present invention having a rigid frame F including an uprightgenerally rectangular portion I mounted" on a flat horizontal base plate2 adapted to be bolted to the floor. The framealso has a horizontalportion 3 overhangingthe upright portion 1 and supporting a pair ofupright end portions 4. A drum assembly Sis mounted between the portions4, and a rotary cutter assembly 6 is mounted on the frame at one side ofthe drum assembly. The cutter assembly includes a main cylindricalspindle 7 rotatably mounted in a horizontal position parallel to thedrum shaft 25. The main spindle is sup- .ported above a horizontal slide8 between a pair of upright end portions 9 carried by the slide. Theslide is mounted in a horizontal position on the horizontal portion 3aof the frame and is guided for sliding movement toward and away from thedrum assembly.

The spindle 7 is driven by means of a drive assembly 11 which includesan electric drive motor 12 having a drive shaft 13 arranged to drive anendless drive belt 14 by means of a lower pulley wheells mounted on theshaft 13 and an upper pulley wheel lfimounted on the spindle 7andarranged to drive the spindle. i A series of externally cylindricalspacer collars 17 are slidably mounted on the cylindrical spindle 7 toprovide means for holding one or more rotary knives 18.'Each spacercollar isin the form of a solid metal cylinder of a predetermined axiallength having an internal diameter corresponding substantially to theexternal diameter of the spindle. These collars may be arrangedend-toend so as to extend the full length of the spindle and they may bearranged to receive a series of rotary knives 18. Each knife isessentially a flat circular disc with a hollow ground peripheral portionwhich is preferably slotted to provide a series of regularly spacedteeth 19 of generally rectangular or trapezoidal shape. The teeth 19 arenot essential and may be omitted because the disc 18 functions as aknife to separate material rather than to cut away material from tubesa. Each knife 18 is attached to fit on the spindle 7 and is attached tothe spindle for rotation therewith by being clamped tightly between apair of collars 17.

A curved sheet metal protective shield 20 is mounted on the slide 8 bymeans of a series of screws 21. The

shield preferably extends the full length of the spindle as indicated inFIG. 1.

Conventional means are provided for adjusting the position of the slide8 relative to the drum assembly 5. As herein shown, a pair of rotatableadjusting handles 22 are provided to effect such movement in ahorizontal direction perpendicular to the drum shaft 25.

The drum assembly includes a cylindrical metal drum 2.4 which extendsaxially a distance several times its diameter as shown in FIGS. l and 2.The drawings herein are drawn substantially to scale to facilitate anunderstanding of the invention, but it will be understood that the sizesof the parts, particularly the thicknesses, may be varied substantially.

The drum 24 is mounted for rotation about a horizontal axia parallel tothe axis of the spindle 7. Any conventional means may be employed toeffect such mounting, and it will be understood that it is not necessaryto employ a shaft for the drum extending the full length of the drum.However, for convenience of illustration, the drum 24 is provided asshown with a shaft 25 which is journaled in the frame at opposite endsof the shaft.

The drum 24 is provided with a series of regularly spaced flat radialvanes 26 of rectangular cross section which extend axially the fulllength of the drum parallel to the axis of rotation. The vanes 26 arerigidly mounted in fixed position around the drum so that all of thevanes project radially the same distance from the periphery of the drum.It will be understood that such vanes may be constructed for radialadjustment so as to accommodate tubes of widely varying diameter, butthis is not essential. I

The drive means for the drum assembly 5 includes an electric drive motor27 and a drive shaft 28 driven by the motor and rigidly connected to adrive sprocket 20. An upper sprocket 30 is rigidly connected to the drumshaft 25 to receive an endless drive chain 31 which is carried by thesprocket 29. The chains and sprockets are preferably covered by aprotective shield or cover (not shown). v Means may be provided forfeeding a series of tubes a one at a time to the drum assembly 5. Suchmeans may, if desired, be provided with conventional escapementmechanisms to feed the tubes one at a time and to prevent cascading, butthis is not essential where the vanes 26 are closely spaced.

As herein shown, the feed means for the drum assembly includes aninclined feed table 32 mounted on a pair of rigid mounting brackets 33which are detachably connected to the upright frame portions 4 by screwsor mounting nuts 34 or the like. A horizontal bar 35 of square crosssection extends between the brackets 33 and is mounted thereon bymounting nuts 36 or other fastening means. A plurality of metal strips37 are rigidly mounted on the bar 35 in an inclined position as shown inFIG. 4 to provide supports for a flat rectangular masonite board 38which forms the tube receiving table. One or more adjustable guide means39 are provided on the upper surface of the board 38 to engage the endsof the tubes a and to guide them as they roll toward the drum. Where thetubes a have a length greater than half the length of the drum, only onesuch guide means 39 is needed, and a row of tubes a may be placed on thetable 32 with the tubes in parallel positions engaging the guide means39. Where it is desired to speed up the rate of production when cutting4 extremely short lengths of tubing, 2. second guide means 39 may beemployed as shown in FIGS. 1 and 2, but this is optional. When a secondguide means is used, an optional dividing bar 44 may be mounted on thecentral portion of the feed table as indicated in FIGS. l. and 2.

As herein shown, each of the guide means 39 comprises a straight metalangle 40 welded to a flat lateral bar 41 having an elongated slot 42.The guide means is rigidly held in its adjusted position by a lockingscrew 43 which extends through the slot into the feed table.

Adjustable guide means 45 are preferably provided in addition to theguide means 39 to guide the tubes a after they have moved on to thedrum. Each guide means 45 is rigidly supported in its adjusted positionon an upwardly extending supporting member 46 which is rigidly mountedon each upright frame portion 4. Each guide means comprises a shortmetal guide member 47 of special shape (see FIG. 4) which is rigidlymounted on the bifurcated end of a rod 48 by means of a pair of rivets58. A supporting arm 49 is provided having an internally cylindrical eye51 which fits on the rod 48 and having a similar eye 52 which fits on ahorizontal stub shaft 53 carried by the adjacent member 46. The arm 49is held against movement relative to the stub shaft by a conventionalset screw 54 in the eye 52 and is rigidly connected to the rod 48 by asimilar set screw 55 in the eye 51.

The guide member 47 is preferably substantially flat and is preferablyprovided with a circular edge surface 56, which may be locatedconcentric to the drum and near the outermost surface of the radial vane26 as shown in FIG. 4. The member 47 preferably extendscircumferentially a substantial distance such as to 90 degrees and maybe tapered generally as shown in the drawings so as to terminate in around nose 57. As herein shown,'two guide means 45 are provided inconnection with two guide means 39, but it will be understood that thesecond guide means is optional and is preferably omitted when themachine is operated in the normal manner with a series of knives 18arranged for multiple cuts. i

The tube cutting machine A is provided with an endless belt assembly 10to effect rotation of the tubes a during the cutting operation. Theassembly 10 includes a pair of upper cylindrical roller shafts 61located in spaced parallel relation and mounted for rotation on themembers 46 about horizontal axes parallel to the shafts 7 and 25. A pairof similar polished external roller shafts 62 are mounted for rotationin a similar manner about parallel horizontal axes. A series of endlessrubber bands 63 are mounted on the hollow shafts 61 and 62'as indicatedin FIG. 4. A horizontal rod 64 of semi-circular cross section extendsbetween the rigid supporting members 46 and is rigidly mounted thereon.The rod has a flat surface 65 on one side thereof and has a crosssection to receive a series of P-shaped band guides 66. Each band guideexpands slightly to receive the rod 64 and tightly grips the rod so thatit resists axial movement and will remain in the desired adjustedposition. The upright straight portion of each band guide 66 extendsdownwardly below the horizontal portion of the endless band 63 whichoverlies the shaft 61 so as to prevent axial movement of the bandrelative to the shaft 61. A pair of band guides 66 are spaced apart adistance slightly greater than the width of the band 63 so as to locatethe band. This is all that is needed to maintain the band so that itoperates substantially in a vertical plane. it will be understood,however, that additional band guides may be employed if desired.

The drive means for the belt assembly includes an electric drive motor67, a gear reduction box 68 having a drive shaft 69 powered by themotor, and a drive sprocket '70 rigidly mounted on the shaft 69.- A pairof upper sprockets 71 are rigidly mounted on the ends of two rollershafts and receive the endless drive chain 72 which is driven by thesprocket 70. The chain and sprockets are preferably covered by aconventional protective shield or cover (not shown).

A generally rectangular control panel 73 is mounted on the machine andsupported by an inclined pipe 74 carried by the frame which receives theelectrical wiring. The control panel has three rows of buttons and apair of lights '75. The light may indicate when the drive motors are onor are ready to operate. A stop and a start button is preferablyprovided for each of the electric drive motors 12, 27 and 67, andadditional control buttons may be provided, if desired, for jogging,changing speed, or stopping all motors simultaneously.

The equipment described above can be used to carry out the conventionaltube cutting process wherein a substantial number of rotary knives 18are mounted on the spindle to out each long tube a into a series ofsections with a length several times the diameter. In performing suchconventional process, the divider bar 44 is omitted, each long bar apreferably extends substantially the full length of the drum, and aseries of endless bands 63 are preferably mounted on the roller shaftsand 62 in regularly spaced rotation to effect rotationof thetubes aduring cutting. The spacing may, for exam ple, be generally as indicatedin FIGS. 1 and 2.

The conventional process may be unsatisfactory, however, when cuttingthe tube a to extremely short lengths, particularly where the axiallength is less than the diameter. It may also be unreliable for cuttingthick-walled tubing with a length less than twice the diameter. Theproblem may sometimes be partially solved by using wider. bands 63 forbetter support during cutting or by using mandrels, but the bands can beno wider than the pieces to be cut andmandrels radically reduce the rateof production.

The present invention involves an improvementin the tube cuttingapparatus which makes an automatic or semi-automatic machine of the typedescribed above suitable for the conventional multi-cut process and alsosuitable for mass production cutting of extremely short lengths (forexample, a length which is only a fractiojn of the external diameter).The additional equipment needed to provide this versatility inaccordance with the invention claimed herein is relatively simple andinexpensive and is described in more detail below. This includes anadjustable stop means 80 and feeding means for advancing the tubes aagainst the stop in response to rotation og the tubes and/or rotationofthe drum 24. A guide means similar to guide means 45 or an extension ofthe latter may also be provided, if desired.

The top means may be of any suitable construction and preferablyincludes a flat stop member 81 perpendicular to the drum axis whichextends a substantial distance (e.g., 20 to 60 degrees or more) aroundthe circumference of the drum. As herein shown, the stop means 80includes a stop member 81 having a shape somewhat similar to that of theguide plate 47 and means for holding the stop member in axially adjustedpositions. The stop means includes an elongated block 82 rigidly mountedon the upright portion 4 of the frame by bolts 63 and having acylindrical bore 84 which receives a slidingrnetal rod or cylinder 85.The end of the bore is closed by an end cap 86 which is internallythreaded to receive an adjusting screw 87 which engages the end ofcylinder 85. A handle 88 is provided on the end of the screw and asimilar handle or locking nut 89 is provided on the screw to lock it inits adjusted position. A pin 76 extends through the cylinder to preventrotation thereof and engages a helical compressing spring '77 in thepin-receiving slot 98 whereby the cylinder is held against the screw 87by spring pressure.

One end portion of the cylinder 85 projects from the block 82 and has acylindrical bore 91 to receive a removable horizontal rod 92. The endportion is split and provided with flanges 93 that receive a lock bolt94 whereby the cylinder may be clamped in the desired position on therod 92 by tightening the bolt. The rod is welded to a collar 95 similarto collar 78 which also fits on the pin 79. The collars 78 and 95 arerigidly held in adjusted positions on the pin by set screws 96. The stopmember 61 may be adjusted radially relative to the drum by changingtheangular position of the rod 92 and collar 95 relative to cylinder 85 andcollar 78. Thus, the stop means 80 provides radial as well as axialadjustment. The stop means has an arcuate edge surface 97 located nearbut out of the path of movement of the vanes 26. The surface 97 may bepositioned concentric to the drum by proper adjustment and may extend asubstantial distance (e.g., 20 .to 80 degrees) around the circumferenceof the drum. As herein shown, the stop member is similar to guide member47 and extends about 70 degrees or so from a position near the planecontaining the axes of the drum shaft 25 and the spindle 7 to a positionnear the end portion 57 of the guide 47.

The tubes a may easily be'fed axially against the stop member 81 inresponse to rotation of the endless belt assembly and the tubes a. Thisis preferably accomplished by applying pressure to one or more of theend less bands 63 or otherwise causing them to be skewed slightly in adirectionto effect axial movement of the tubes a. As shown in FIG. 4,such skewing is effected byan adjustable arm 100 having a pin 10]projecting therefrom and engaging the adjacentband 63. The pin deflectsthe bowed portion 1050f the band to maintain the lower horizontalportion 102 of the band below rollers 62 a fraction of an inch (forexample, one-eighth to one-half inch) out of vertical alignment with theupper horizontal portion 103 of the band. Theposition of the latterportion is determined by the two band guides 66 at opposite sides ofportion 103. The skewing of the deflected band portion also results indeflection of the straight upright portion 104 of the band but to alesser degree As herein shown, only the outermost band 63 is skewed, butit will be apparent that two or more of even all of the bands63 will beskewed in a similar manner using arms 100 or other suitable means todefect the band portions 105. Where the outer band 63 is only skewed andthe remaining bands are straight, the latter bands resistthe axialmovement of the tubes a somewhat but ordinarily not enough to materiallyaffect the operation of the machine, particularly when relatively narrowbands are used.

As herein shown, each arm 100 is adjustably' mounted in an inclinedposition by a bracket 106 which is rigidly connected to the frameportion 3 by a screw 107. The arm is connected to the inclined portionof the bracket by an adjusting screw 108 which is tightened by a wingnut 109 to clamp the arm rigidly in the desired adjusted position withthe pin 101 engaging the belt 63 generally as indicated in FIG. 4, forexample.

Ordinarily the machine A requires only one arm 100 and one rotary cutter18 (omitting center guide 44), but faster operation can be effected bythe arrangement illustrated in the drawings wherein a second cutter 18is employed and an optional second arm 100 is provided which is locatedmirror-symmetrically relative to the first arm 100 to skew itsassociated belt 63 in the opposite direction to effect axial feeding ofthe tubes toward the optional second stop 81 (see FIGS. 1 and 2).

Means are provided for holding the tubes a on the drum 24 after theymove out of contact with the belts 63 so that they will be returned tothe knife 18 for subsequent cuts. Such means may be of various types andmay be mounted on and rotatable with the drum as in the modified form ofFIGS. 8 to 10. Such means preferably comprise a plurality of removablesheet metal straps 110 or the like bent around the drum to prevent thetubes a from falling off the drum. The straps have smooth surfaces sothey do not interfere with rotation of the tubes a. I

As herein shown, each strap 110 is a smooth metal strip of uniform widthand thickness having a flat fixed end 111 connected by screws 112 to thebar 35 of the feed table and having an eye 113 at-its upper enddetachably connected to the bar 64 by a ook 114 and a helical tensionspring 115. At least one and preferably a series of straps 110 areemployed as shown in FIGS. 1 and 2, for example.

When it is desired to adjust the machine A of FIGS. 1 to 7 for cuttingof the tubes d into sections having lengths of several inches or manytimes the diameter of the tube, the straps 110 are removed and a seriesof rotary knives or cutters 18 are mounted on the spindle 7, each knifebeing spaced axially from the next knife by the collars 17 a distanceequal to the desired length of the cut tube. The dividing bar 44 is thenomitted, and each tube a fed from the table 32 to the drum assemblypreferably extends substantially the full length of the drum. The vanes26 are adjusted radially to project from the peripheral surface 23 ofthe drum a distance greater than the radius and less than the diameterof each tube a.

With the equipment adjustment for multiple cutting as described above,each tube a is placed on the feed table 32 parallel to the axis of thedrum 24 in a single row and moves toward the drum as the other tubes ina row are fed one at a time to the drum. The vane 26 lifts the lowermosttube a from the row at table 32 and advances it around the drum towardthe rotary knives. With equipment of the type illustrated herein, thevanes can escape the tubes a one at a time from the feed table to thedrum without separate escapement means. It will be understood, however,that conventional escapement means can be employed at the dis charge endof the table 32 as is well understood in the art.

As shown in FIG. 4, the axis of each tube 0 moves with the drum morethan 90 degrees in a clockwise direction from the discharge end of thetable 32 before the tube engages the endless bands 63 and then moves atleast 30 degrees more while the tube is in contact with the bands beforethe tube engages the knives 18. The bands 63 cause the tube a to rotateat an angular speed many times that of the drum 24 so that the tubemakes at least one complete revolution while in contact with the knives18, whereby severing is effected before the tube moves out of contactwith the knives. Each of the severed tube sections engages one of therubber bands 63 and is held on the drum until it moves out of contactwith the band. With the straps 110 removed, these tube sections are freeto fall and are preferably caught in a conventional chute (not shown)located below the drum.

In the machine shown in the drawings, each band 63 has a deflectedportion 105 which remains in contact with a tube a on the drum 24 whilethe drum turns about one-quarter revolution and which causes the tube torotate several times during such contact. It will be apparent, however,that the amount of contact and the speed of movement of the band 63relative to the drum 24 may be varied considerably.

The rotary knives 18 are adjusted horizontally toward or away from thedrum by turning the handwheels 22 to move the slide 8 in or out. Inorder to cut off the tube sections it is necessary to position thespindle 7 so that the peripheral edge of each knife projects to orbeyond the internal surface of the tube. When adjusted as shown in FIG.5, for example, the peripheral edge of each rotary knife 18 is spacedfrom the peripheral surface 23 of. the drum a radial distance which maybe greater than the internal diameter of the tube a and is preferablyslightly less than said internal diameter plus the wall thickness of thetube. Such radial distance may be less than the internal diameter of thetube a so that the cutting portion 19 of the knife projectsasubstantialdistance through the tube wall, but better cutting may usually beobtained when such projection is minimized. The knife should not engagethe vanes 26, and the vanes are preferably adjusted to avoid contactwith the knife or contact with the bands 63. However, the vanes can beprovided with slots to receive the knife when the tubes a have a verysmall diameter.

The conventional multiple-cutting operation is usually satisfactory solong as the tube sections being cut have a length at least several timsthe tube diameter. Where the cut sections are short, it is oftendesirable to provide soft rubber bands 63 with a substantial width, suchas 1 to 3 times the tube diameter, to provide better support duringcutting, but such width must be less than the length of the cut. Widebands 63 are not needed, however, when the cut sections are relativelylong. The normal width of each band 63 is about onequarter inch.

When the sections to be cut from tube a have a length substantially lessthan twice the external diameter of the tube or less than such diameter,the conventional multiple-cutting operation described above may not befeasible. In that case the machine A is adjusted for use with the straps110, at least one arm to hold one of the belts in a skewed position, andat least one stop 81 so that one piece is cut off the end of each tube aduring each revolution of the drum 24.

The machine A may be operated with one knife 18 I to cut at one end onlywhen using one arm 100 and one skewed belt or using belts skewed in onlyone direction 9 so that the second stop 81 and the second guide means 39are not needed and may be omitted. In such case the divider 44 ispreferably omitted to permit use of tubes a with a length substantiallygreater than half the length of the drum.

Higher speed operation is possible when operating the machine A with tworotary knives 118 as illustrated, for example, in FIG. I of thedrawings. Although this is not necessarily the preferred method, theoperation of the machine in this manner will be described below, itbeing readily apparent how the machine may be operated with one knifeonly instead of two.

In the embodiment of the invention illustrated in FIGS. 1 to 7, asubstantial number of tubes a with a length somewhat less than half theaxial length of the drum 24 are placed in rows on the inclined table 32with their ends near the guides 39. The tubes are allowed to roll towardthe rotating drum 24 where they are picked up by the vanes 26 one at atime. Each tube a engages the drum and is lifted and advanced toward therotary cutter unit 6. As it advances the end of the tube can engage theguide 47 to move the tube a short distance axially in response torotation of the drum.

When the tube moves beyond the guide 47 into engagement with the endlesselastic rubber bands 63, it is caused to rotate and forced againstthesmooth surface of the associated vane 26 as indicated in FIG. 5. Theoutermost band 63 is skewed bythe pin 101 which holds the lower portion102 of the band a fraction of an inch (for example,0.2 'to 0.3 inch) outof vertical alignment with the upper portion 103, which is held by theguides 66. The skewed band engagesthe tube a and advances it axiallyagainst the stop 81 before the tube engages the knife 18. The axialfeeding by the skewed band is very effective and will position the tubesa properly against the stop even when the ends of the tube on the table32 are out of alignment by a substantial amount (for example, 1 inch to1.5 inches or so).

It is, therefore, possible to operate efficiently even without theguides 47.

As the rotating tube a continues to move downwardly with the drum towardthe line of centers of the drum and the spindle 7, it engages therotatingknife l8 which effects cutting by material displacement. This isnot a sawing operation and there is little removal of material,

although some dust may be produced during the cutting. The cuttingportion 19 of the knife is preferably slotted to provide teeth but thisis not essential. It will be understood, however, that the knives 18 maybereplaced with saws for special jobs.

The knife 18 is preferably located so that it projects past the innerspace of the tube being cut only a very short distance, such as 0.01 to0.02 inch, to avoid forming a burr but it may project a greaterdistance, such as 0.05 to 0.06 inch, if the periphery of the tube a isuneven. lt can project a much greater distance if a burr is considereddesirable. i

The knife is spaced from the stop 81 a distance corresponding to thedesired length of the pieces to be out (see FIGS. 6 and 7).-When cuttingwashers or the like, I

the knife may be a small fraction of an inch from the stop.

While the tube a is in contact with the knife, it is rotated at leastone revolution by the bands 63. Therefore, the tube is cut all the wayaround its circumference, and the washer or'other piece between theknife and the stop hl is severed before the tube moves out of contactwith the knife. The cut piece is allowed to fall and may be caught in asuitable receptacle or chute below the drum.

After the piece is severed, the remainder of the tube a is held againstthe drum by the smooth metal straps 1110 so that it can be advanced 300degrees or more around the drum by the vanes 26 for a subsequent cut. Asit approaches and moves into engagement with the bands 63, its cut endmay be spaced from the stop a substantial distance. The skewed band 63moves it axially, however, so that the cut end engages the stop beforethe second cut begins.

The cutting is repeated once each revolution of the drum until only ashort piece remains. In order to minimize waste, the outermost skewedband 63 is spaced a very short distance from the knife (for example, onequarter to one-half inch or less) and the outermost strap is likewiseclose to the skewed band as shown, for example, in FIGS. 6 and 7 (forexample, within one inch of the knife). With this arrangement the skewedband 63 can effect the desired rotation during cutting even when theremaining tube is very short. Eventually the remaining tube is too shortto be held by the straps llltl and will fall off the drum as waste.

The stop 81 preferably terminates near the line of centers of thespindle 7 and the drum shaft 25 so that the severed piece can fallfreely when the cutting is completed. This also allows the skewed beltto move the remainder of the tube a short distance axially toward thestop during the short movement (for example,'20 to 25 degrees) in thebrief period from the time the tube passes the stop until it movesdownwardly out of engagement with the belts 63.

The above description applies to the operation at each end of the drum24 when leftand right-hand stops 81 and oppositely skewed belts 63 areemployed as in the species of FIGS. 1 and 2.

It is preferable to load the drum with the proper number of tubes a sothat the feed table 32 is empty during the cutting operation. However,conventional escapement means may be provided for holding the tubes onthe table during cutting if fully automatic operation is desired.Likewise, a hopper 125 may be provided to maintain a supply of tubes asindicated in dot-dash lines in FIG. 3.

It will also be understood that the tubes a may be fed to the tubecutting machine of this invention by a conventional bar feeder having aconventional automati cally controlled escapement mechanism at the endof the feed ramp. Such bar feeders and escapement mechanisms aredisclosed, for example, in US. Pat. Nos. 3,480,159; 3,493,125; 3,506,142and 3,581,879.

' FIGS. 6 to 30 show a modified form of tube cutting machine A, whichmaybe the same as the machine A except that the straps 1110 are removedand a series of metal tubes are welded to or otherwise rigidly mountedon the drum 24. Any number of tubes 120 may be mounted on the drum,preferably a substantial number as indicated in FIG. 8, for example.Only one arm 100 and one skewed belt 63 is used in this embodiment sothat the tube a extends the full length of the tube 120, but it will beunderstood that two arms 100 and two skewed belts may be used if shortertubes a are used and loaded into both ends of each tube 120.

Each tube 120 has one or more and preferably a series of slots thereinto receive the rotary knives l8 and the belts 63 during the end-cuttingoperation or the more frequent multiple-cut operation. As herein shown,each tube has at least one slotted portion 121 for this purpose whichterminates in a shoulder 122 a short distance beyond the belt 63 (seeFIG. 9). The numer of slots in the metal tube 120 corresponds to thenumber of belts and would be six in a machine of the type shown in FIGS.1 and 2.

Long tubes of small diameter made of paper or synthetic plastic materialare slid into the metal tubes 120 by a manual loading process while thedrum is slowly indexed. This is a slow procedure but makes it possibleto cut stringlike rods or tubes of extremely small diameter which couldnot otherwise be cut on the machine. For example, it may be possible tocut tubes with a diameter of 0.01 inch and a wall thickness of around0.002 inch to short lengths such as 0.1 to 0.2 inch.

The size of the metal tubes 120 depends on the size of the tubing to becut. Usually the internal diameter of tube 120 will be about 0.1 inch to0.2 inch. The slot at 121 preferably has a radial depth at least 0.4times the outside diameter or sufficient to permit proper driving of thetube a by the belt 63 and cutting of the tube without damage to theknife 18. If desired, narrow notches may be provided in the tube 120 toreceive the knife. However, this is not necessary where each knife 18 ispositioned adjacent one of the belts 63.

in the arrangement shown in FIG. 9, a skewed belt 63 is located near thestop 81. It will be understood, however, that the stop may be omittedand the arm for belt 63 also omitted when performing a multiple-cuttingoperation with a series of knives 18.

The rods or tubes a and a are usually made of a material which is easilycut by a knife such as paper, cardboard, plastic, rubber or the like,but it will be understood that the process of this invention may beapplied to the cutting of harder materials, including metals, and to thecutting of solid rods.

It will be understood that, in accordance with the provisions of thepatent laws, variations and modifications of the specific'methods anddevices disclosed herein may be made without departing from the spiritof the invention.

Having described my invention, I claim:

1. A machine for mass-producing both medium and short lengths of tubingfrom long tubes without use of mandrels to support the tubes comprisinga rotary drum having at least eight radial vanes spaced apart to receiveloosely a multiplicity of long empty tubes (a), a spindle parallel tosaid drum for supporting a series of flat rotary knives, said spindlehaving at least four cylindrical collars mounted thereon in end-to-endrelation and adapted to' clamp one of said knives between each pair'ofsaid collars for multiple-cutting operations, a series of endless banddriving means spaced axially along the length of said drum, each drivingmeans comthe end of said drum for engaging the end of each tube duringthe cutting of that tube, removable means for holding the empty tubes onthe drum as they move under the drum, one endless belten'gag'ing theperiphery of the tube within one inch of said stop, means for engagingsaid one belt to deflect it axially and to skew the belt in a directionto cause each empty tube to be advanced axially toward said stop inresponse to rotation of the tube, one rotary knife being located axiallybetween said stop and said one belt and adjacent said belt, said knifeprojecting part-way into the tube during the cutting operation, saidstop having an adjusted position spaced axially from said rotary knife adistance less than twice the diameter of the tube, whereby the samemachine can be used with one rotary knife near said stop for massproduction cutting of very short lengths of tubing and can be used witha series of rotary knives for multiple cutting of longer lengths oftubing.

2. A mass-production tube-cutting machine according to claim 1 whereinmeans are provided for feeding the tubes laterally to the drum includingan inclined feed table at one side of the drum.

3. A machine according to claim 2 wherein said re movable meanscomprises a series of axially spaced strips under the drum for engagingthe tubes to hold them on the drum.

4. A machine according to claim 3 wherein said stop had an adjustedposition spaced axially from said knife at a distance less than theradius of the tube.

5. A machine according to claim 2 wherein a stop, a rotary knife and askewed endless belt are provided at each end of the drum so that a tubeis advanced against a stop and cut by a rotary knife in the same way ateach end of the drum. n

6. Apparatus as defined in claim'l wherein said drum has at least 30long metal pipes mounted on the periphery of the drum to receive saidtubes, each pipe having an opening therein to receive said rotary knife.

7. Apparatus as defined in claim 6 wherein each pipe has an internaldiameter of about 0.1 to 0.2 inch and extends substantially the fulllength of said drum.

8. Apparatus as defined in claim '1 wherein said stop isspaced a shortdistance radially from the periphery of said drum, means are providedfor holding the stop in fixed axially spaced adjusted positions alongthe length of the drum, and means areprovided for adjusting the radialdistance between said stop and said drum. 1;

1. A machine for mass-producing both medium and short lengths of tubingfrom long tubes without use of mandrels to support the tubes comprisinga rotary drum having at least eight radial vanes spaced apart to receiveloosely a multiplicity of long empty tubes (a), a spindle parallel tosaid drum for supporting a series of flat rotary knives, said spindlehaving at least four cylindrical collars mounted thereon in end-to-endrelation and adapted to clamp one of said knives between each pair ofsaid collars for multiple-cutting operations, a series of endless banddriving means spaced axially along the length of said drum, each drivingmeans comprising a pair of spaced rollers above said drum, a pair ofspaced rollers below said drum, an endless belt extending around saidrollers and having a deflected portion extending between the upper andlower rollers for engaging the periphery of each tube to rotate the sameduring cutting, and means for driving at least one of said rollers torotate the belt, an adjustable stop near the end of said drum forengaging the end of each tube during the cutting of that tube, removablemeans for holding the empty tubes on the drum as they move under thedrum, one endless belt engaging the periphery of the tube within oneinch of said stop, means for engaging said one belt to deflect itaxially and to skew the belt in a direction to cause each empty tube tobe advanced axially toward said stop in response to rotation of thetube, one rotary knife being located axially between said stop and saidone belt and adjacent said belt, said knife Projecting part-way into thetube during the cutting operation, said stop having an adjusted positionspaced axially from said rotary knife a distance less than twice thediameter of the tube, whereby the same machine can be used with onerotary knife near said stop for mass production cutting of very shortlengths of tubing and can be used with a series of rotary knives formultiple cutting of longer lengths of tubing.
 2. A mass-productiontube-cutting machine according to claim 1 wherein means are provided forfeeding the tubes laterally to the drum including an inclined feed tableat one side of the drum.
 3. A machine according to claim 2 wherein saidremovable means comprises a series of axially spaced strips under thedrum for engaging the tubes to hold them on the drum.
 4. A machineaccording to claim 3 wherein said stop had an adjusted position spacedaxially from said knife at a distance less than the radius of the tube.5. A machine according to claim 2 wherein a stop, a rotary knife and askewed endless belt are provided at each end of the drum so that a tubeis advanced against a stop and cut by a rotary knife in the same way ateach end of the drum.
 6. Apparatus as defined in claim 1 wherein saiddrum has at least 30 long metal pipes mounted on the periphery of thedrum to receive said tubes, each pipe having an opening therein toreceive said rotary knife.
 7. Apparatus as defined in claim 6 whereineach pipe has an internal diameter of about 0.1 to 0.2 inch and extendssubstantially the full length of said drum.
 8. Apparatus as defined inclaim 1 wherein said stop is spaced a short distance radially from theperiphery of said drum, means are provided for holding the stop in fixedaxially spaced adjusted positions along the length of the drum, andmeans are provided for adjusting the radial distance between said stopand said drum.